Embodiments disclosed herein relate to methods for enhancing purification of proteins, including antibodies. They particularly relate to methods for reducing the level of aggregates and can be combined with methods of cell culture harvest clarification. They further relate to integration of these capabilities with other purification methods to achieve a desired level of protein purity.
Aggregate removal is an important aspect of protein purification. It has been shown that low concentrations of the yellow fluorescent heterocyclic dye ethacridine reduces aggregate content of antibody preparations, and that this result may be due, in part, to chromatin removal (Gan et al J. Chromatography A 1291 (2013) 33-40). Ethacridine has a long history as a protein precipitating agent.
The surfactant cetrimonium bromide is used as a topical antiseptic. It is also used in the production of gold nanoparticles, and widely in hair-care products. It is used in the field of protein analysis where it improves resolution of complex glycoproteins in polyacrylamide gel electrophoresis, and in DNA extraction. It is not known to have applications in the field of protein fractionation.